def ComputeChecksum(data_bytes):
""" Compute Base58 checksum.
Args:
data_bytes (bytes): Data bytes
Returns:
bytes: Computed checksum
"""
return CryptoUtils.Sha256(
CryptoUtils.Sha256(data_bytes))[:Base58Const.CHECKSUM_BYTE_LEN]
def FromEntropy(entropy_bytes: bytes) -> str:
""" Generate mnemonic from the specified entropy bytes.
Args:
entropy_bytes (bytes): Entropy bytes (accepted lengths in bits: 128, 160, 192, 224, 256)
Returns:
str: Generated mnemonic from specified entropy
Raises:
ValueError: If entropy length is not valid
"""
# Check entropy length in bits
entropy_bit_len = len(entropy_bytes) * 8
if entropy_bit_len not in Bip39Const.ENTROPY_BIT_LEN:
raise ValueError("Entropy length in bits (%d) is not valid" %
entropy_bit_len)
# Compute entropy hash
entropy_hash_bytes = CryptoUtils.Sha256(entropy_bytes)
# Convert entropy to binary string
entropy_bin = ConvUtils.BytesToBinaryStr(entropy_bytes,
len(entropy_bytes) * 8)
# Convert entropy hash to binary string
entropy_hash_bin = ConvUtils.BytesToBinaryStr(
entropy_hash_bytes,
CryptoUtils.Sha256DigestSize() * 8)
# Get checksum binary string
checksum_bin = entropy_hash_bin[:len(entropy_bytes) // 4]
# Create mnemonic entropy binary string by concatenating entropy and checksum, as specified in BIP39
mnemonic_entropy_bin = entropy_bin + checksum_bin
# Create mnemonic reader
mnemonic_reader = MnemonicFileReader()
# Empty mnemonic
mnemonic = []
# Get mnemonic from entropy
for i in range(len(mnemonic_entropy_bin) // Bip39Const.WORD_BITS):
# Get current word index
word_idx = int(
mnemonic_entropy_bin[i * Bip39Const.WORD_BITS:(i + 1) *
Bip39Const.WORD_BITS], 2)
# Get word at given index
mnemonic.append(mnemonic_reader.GetWordAtIdx(word_idx))
# Join to string
return " ".join(mnemonic)
def __ComputeChecksum(self, mnemonic_bin_str):
""" Compute checksum from mnemonic binary string.
Args:
mnemonic_bin_str (str): Mnemonic binary string
Returns:
bytes: Computed checksum binary string
"""
# Get entropy bytes
entropy_bytes = self.__GetEntropyBytes(mnemonic_bin_str)
# Convert entropy hash to binary string
entropy_hash_bin = ConvUtils.BytesToBinaryStr(CryptoUtils.Sha256(entropy_bytes), CryptoUtils.Sha256DigestSize() * 8)
# Compute checksum
checksum_bin = entropy_hash_bin[:self.__GetChecksumLen(mnemonic_bin_str)]
return checksum_bin